An LED lamp includes a transparent bulb, an LED module comprising a plurality of LEDs received in an inner space of the bulb, and a heat dissipation apparatus supporting and cooling the LED module. The heat dissipation device includes a heat sink having a hollow base and a plurality of fins extending from the base, a first heat conductor vertically supported by the heat sink, a second heat conductor horizontally mounted on the first heat conductor, and a heat pipe thermally connecting the heat sink, the first heat conductor and the second heat conductor together. The LEDs are positioned on the first heat conductor and the second heat conductor, respectively.